1. Field of the Invention
The present invention relates to a magazine for supplying connected nails, which are connected in a plane-shaped condition, to a nail gun capable of driving two or more different-length nails.
2. Description of the Related Art
FIG. 1 shows a nail gun 101 that includes a drive portion 102, a nose 103, and a magazine body 104. Although not shown in the drawings, the drive portion 102 includes a cylinder, a piston, and other components for generating a force for driving nails into a work piece. The nose 103 is for guiding nails 108 that are driven by the drive portion 102 toward the work piece. The magazine body 104 stores a plurality of nails 108 and includes a feeder 105. The feeder 105 feeds nails 108 one after the other to the nose 103.
As shown in FIG. 2, the nails 108 are supported by a connection band, such as tape, in a plane-shaped group of connected nails 107. Each nail includes a nail head 108a and a nail shaft 108b, the nail head 108a being larger than the nail shaft 108b. 
The nail gun 101 of FIG. 1 can use two different-length nails 108A, 108B, shown in FIGS. 3 and 4, respectively. The appropriate nail length depends on the thickness of the work piece, such as a wooden board, to be fixed in place. For example, inexpensive short nails 108B are preferred when the work piece is thin, because a thin work piece can be fixed in place without a great deal of supporting force. On the other hand, longer nails 108A need to be used to provide sufficient supporting force when the work piece is thick.
Because different driving energy is required for different length nails, a pressure reducing value is provided to adjust to the proper air compression force required for driving the currently loaded nail type 108A, 108B into the current work piece.
As shown in FIGS. 3 and 4, the magazine body 104 is formed with upper and lower guide rails 106a, 106b that enable supply of the different-length nails 108A, 108B. The upper and lower guide rails 106a, 106b guide the nail head 108a of the nails 108A, 108B so that the lower nail tip of both the long and short nails 108A, 108B is disposed at the same predetermined level.
However, the length of nails that are presently loaded in the magazine body 104 cannot be confirmed from outside of the magazine body 104. Therefore, it is difficult for an operator to judge whether the length of the current nails 108 is a proper match for the work piece to be fixed in place. As a result, the operator may operate the nail gun 101 to drive a nail with an improper length into the work piece.
Also, because it is impossible for the operator to confirm the length of the currently housed nails, the operator might erroneously load short nails 108B while long nails 108A are currently in the magazine body 104, or load long nails 108A while short-nails 108B are currently in the magazine body 104. This would result in two different length nails being housed in the magazine body 104 at the same time. When the nail gun 101 is operated repeatedly in this condition, then nails with different lengths may be driven immediately one after the other before the pressure reducing valve can change the drive force. As a result, a long nail 108A may be only partially driven into the work piece because the drive force is insufficient. On the other hand, a short nail 108B may be driven too deeply into the work piece, thereby forming an indentation in the work piece around the nail, because the driving force was excessive. Both of these conditions lower the supporting force for fixing the work piece in place. Also, the load on the nail gun 101 increases, thereby shortening the life of the nail gun 101.
It is an objective of the present invention to overcome the above-described problems and to provide a magazine that prevents different length nails from being erroneously mounted into the magazine body at the same time and that enables an operator to confirm the length of the nails currently housed in the magazine body.
To achieve the above-described objectives, a magazine according to the present invention includes a magazine body for supporting nails; a feeder for pressing nails supported in the magazine body to feed the nails toward a nose-side end of the magazine body; a nail gate movably disposed at a nail loading opening of the magazine body, and selectively allowing insertion long and short nails into the magazine body depending on position of the nail gate; and a nail gate movement prevention means that prevents movement of the nail gate while nails are supported in the magazine body.
It is describable that the movement prevention means include a wire and a spring. The spring presses the wire into engagement with the nail gate while nails are supported in the magazine body. The feeder presses the wire away from, and out of engagement with, the nail gate while no nails are supported in the magazine body.
It is desirable that the nail gate be colored differently from the color of magazine body.
It is desirable that the nail gate be provided with a recognition mark and the magazine body be provided with a plurality of nail length indications. The position of the nail gate aligns the recognition mark with a nail length indication that indicates length of nails presently insertable into the magazine body.
It is desirable that the magazine body include nail head supporting passages for supporting heads of nails loaded into the magazine body. The nail pressing portion of the feeder presses against a shaft portion of nails at a position below the nail head supporting passages so that only nails mounted with heads in nail head supporting passages proper for length of the mounted nail are pressed.